From my experience with Binance, bitmex and OKEX, i come up with the following analysis.
Binance:
Good - the OG of crypto exchanges, wide range of trading pairs, relatively reliable.
Bad - suffer from security issue
OKEX:
Good - lots of promotions, airdrops, relatively cheap fees, wide range of products
Bad - too many promotions!
Bitmex:
Good - high risk high return derivatives
Bad - price manipulation
My two cents about the 'bad' that you specified;
Binance; They did suffer from security problems, but they are fixed. Any new security problems that may occur are just as much of a risk on other platforms.
OKEx; It's a crappy Tether wash trading exchange. Too many promotions is the last "problem" to worry about when using them.
Bitmex; I do agree that there is an increased incentive for the exchange to manipulate the prices and front run orders of other traders because of their in-house trading bots.
I personally would never use or recommend anyone to use OKEx because they are just a shady exchange. BTI report about wash trading can be found here.
Hahaha, that's some good input you have right there! Thanks for the BTI report! Look like a reliable source of information.
BTW, how to be "BTI verified"?